Most countries around the world conduct a regular National Census. Censuses date back to biblical times. A big reason for them has always been the need to understand how many people should be paying taxes and how much! These days the reasons are a little more sophisticated. Mostly censuses provide information to help governments plan where to build services such as schools and hospitals, and how to do the best job of formulating strategic plans and policies.

One of the most exciting features of census data is the ability to undertake time series analysis. Knowing the total population of a country is one thing, but knowing that the population has increased or decreased since the last census is far more important. GIS professionals become useful here because a further vital piece of information in this puzzle is “where” population has changed. Notice I use the word “changed” rather than “increased”. I use the term “changed” because the population in any country is unlikely to increase or decrease uniformly. In some places the population will decline, and in other places the population will increase.

These days most of the census agencies make their data available online and for free. Many agencies also have map viewers. Ahhh, you say. But how could GIS folk be useful when most of this information is mapped online anyhow? My answer to this is that there’s plenty of need for GIS analysts (people who understand the problem being mapped but who also have a grasp of GIS technology) because…

Few of the planners who want and need to use census information have the time, inclination or aptitude to retrieve and format it.

Census agencies tend to only publicly release the bits of their datasets that people will use the most. Specialist government agencies require specialist information to help answer their niche questions. Specialty census data are provided on a request-by-request basis and its GIS analysts who make this useful to an organization.

Many organizations have their own data that needs to be related to the census. For example, a realtor might want to compare house prices to incomes in an area. GIS professionals would be needed to map house sales, and then to relate them to the census.

And then there’s the issue of understanding the mapping aspects of census data. Census bureaus change their analytical boundaries and the questions they ask all the time, meaning that special skills are required to make sure its use reflects an understanding of these issues.

As you can see, Analysis of the census using GIS is an important geography career indeed. And just because much of the census is online, that doesn’t mean that there are fewer GIS jobs, but rather, probably more!